Debt - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Components of interest expense
Contractual coupon interest	$ 37,304	$ 2,154	$ 110,230	$ 6,201
Non-cash interest expense (including amortization of discounts, deferred financing costs, and PIK)	11,504	308	31,466	896
Total interest expense	$ 48,808	$ 2,462	$ 141,696	$ 7,097